If you want to use it just for yourself, you can change the URL in line 24 in the index.html into the php's URL. Then you should put the php in a proper place.( You'd better put the php into the same folder with HTML txt);
If you want to make others use it, you can change the URL in line 24 in the index.html into the php's URL. Then you should put the php in a server that other people can link to.